1. Field of the Invention
The present invention relates generally to a method for charging one or more electronic devices and a charging device thereof.
2. Description of the Related Art
Because of recent remarkable developments in the areas of information, communication, and semiconductor technologies, the dissemination and utilization of various mobile terminals has increased rapidly. In particular, recent mobile terminals have reached a point of mobile convergence where mobile terminals can now cover functionality that was traditionally performed by other types of terminals in addition to their own unique functionality. For example, a mobile communication terminal may have a variety of additional functions, such as a television (TV) viewing function (e.g., mobile broadcasting, such as Digital Multimedia Broadcasting (DMB) or Digital Video Broadcasting (DVB)), a music playback function (e.g., MPEG Audio Layer-3 (MP3)), a photo shooting function, and an Internet access function, in addition to general communication functions, such as a voice call function and a messaging function.
Many mobile terminals are capable of receiving power wirelessly through a charging device.
FIG. 1 illustrates a first and second electronic device, which are wirelessly charged by a charging device, according to the prior art.
Referring to FIG. 1, a first electronic device 120 and a second electronic device 130 are put on a charging device 110 that is implemented in the form of a charging pad. Since the charging device 110 is a wireless charging device, the charging device 110 charges the first electronic device 120 and the second electronic device 130, simply by the user placing the first electronic device 120 and the second electronic device 130 on the charging device 110. If power is input through an input port 111 of the charging device 110, a current flows in a coil of the charging device 110. As resonant coupling occurs between the coil of the charging device 110 and coils of the first electronic device 120 and the second electronic device 130, and a current of the charging device 110 is delivered by the resonant coupling to the first electronic device 120 and the second electronic device 130 that are placed on the charging device 110, the power of the charging device 110 may be delivered to the first electronic device 120 and the second electronic device 130.
FIGS. 2A and 2B illustrate how the electronic device 130 is wirelessly charged with power by the charging device 110 according to the prior art. It will be assumed in FIGS. 2A and 2B that the electronic device 130 is a wearable device that is implemented in the form of a wristwatch.
Referring to FIG. 2A, an electronic device 130 is provided with power from the charging device 110, when the electronic device 130 is placed on the charging device 110. As mentioned above, the power charging between the charging device 110 and the electronic device 130 may be performed by the resonant coupling between the charging device 110 and the electronic device 130. Since the electronic device 130 is implemented as a wristwatch-type wearable device, the electronic device 130 may be placed on the charging device 110 in a manner where the electronic device 130 rests on its side while on the charging device 110, as shown in FIG. 2A.
Referring to FIG. 2B, an angle between a receiving (Rx) resonator 135, including a coil of the electronic device 130, and a transmitting (Tx) resonator 115, including a coil of the charging device 110, is A°. The angle A° may be, for example, 90°.
Since the angle between the Tx resonator 115 and the Rx resonator 135 is A°, the angle between the coil included in the Tx resonator 115 and the coil included in the Rx resonator 135 is also A°. Charging efficiency is higher when the area in which the coils included in the resonators 115 and 135 are facing each other is wider. Since, in FIGS. 2A and 2B, the area in which the Tx resonator 115 and the Rx resonator 135 face each other is very narrow, the charging efficiency of the Tx resonator 115 and the Rx resonator 135 will be low. Due to the low charging efficiency, a lot of time is required to fully charge the electronic device 130, and the charging device 110 must supply a lot of power to the electronic device 130 in order to charge the electronic device 130. Accordingly, there is a need for a more efficient method of charging an electronic device.